Wide-area distance protecting method for transformer substations

The invention discloses a wide-area distance protecting method for transformer substations. The wide-area distance protecting method for the transformer substations comprises the steps that a master station-substation protection control system comprising a master station and multiple substations is established in a regional power grid; on-site judgment of wide-area distance protection is completed by the substations with the transformer substation with secondary direct-current power supply disappearing and a line connected with the transformer substation as protection targets, and the information is uploaded to the master station; after the master judges that a certain transformer substation loses power, wide-area distance protection of the power-losing area of the transformer substation is completed according to the on-site information uploaded by the substations, and then faults in the power-losing area of the transformer substation are isolated rapidly. According to the wide-area distance protecting method for the transformer substations, when the serious accident that the secondary direct-current power supply of the transformer substation in the power grid disappear, the faults in the power-losing area in the transformer substation can isolated rapidly, and safe and stable operation of the power grid is guaranteed.